Embodiments of the disclosed technology relates to a method for preventing electrostatic breakdown, a method for manufacturing array substrate and a display substrate.
Liquid crystal displays (LCDs) are currently commonly-used flat panel displays, among which thin film transistor liquid crystal displays (TFT-LCDs) are main products.
Electrostatic breakdown is a very common failure mode in electronic industry. Electrostatic breakdown is a phenomenon in which charges are concentrated on one part of a device and generate electrostatic discharge. Electrostatic breakdown may lead to serious damage to a TFT-LCD device and thus should be avoided in the manufacturing process of the TFT-LCD device.
The conventional method for preventing electrostatic breakdown in the TFT-LCD industry is to prepare an electrostatic ring. An electrostatic ring is based on the principle that electrostatic charges tend to distribute along the outer edge of a conductor. A ring circuit is provided along the peripheral of the array substrate of a single liquid crystal panel, and gate lines, common electrode lines and data lines are connected to the electrostatic ring through a TFT structure in which source or drain is connected with gate. Thus, when there is excessive amount of electrostatic charges over any conductive line among the gate lines, the common electrode lines and the data lines, the TFT device connected between the line and the electrostatic ring may be automatically turned on and the electrostatic charges are led to the electrostatic ring, thereby the liquid crystal panel is protected.
However, the TFT structures, connecting with the gate lines, the common electrode lines and the data lines, on the electrostatic ring function until the whole array substrate has been manufactured. Therefore, the electrostatic ring cannot perform the function of preventing electrostatic breakdown during the manufacturing process of the array substrate. However, during the manufacturing process of the array substrate, it is very likely for the electrostatic charges to arise in the chemical vapor deposition (CVD) process and the dry etching process and thus generate electrostatic breakdown, the product yield may be reduced.